Stapling machine



April 29, 1941. R. G. HOFFERT 2,239,963

STAPL'ING MACHINE Fled'Aug. 17, 1938 56 54 2 39 X05 L Y' )l J5 M 12gi f545 55:' 57 55 Z3 2 2 l i5 024? S 7 25 5X6 28 l 42 l J5 Z/v, 4,22 6kATTORNEY.

Patented Apr. 29, 1941 STAPLING MACHINE Roy G. Hoffert, Racine, Wis.,assignor to Ajax Tool and Die Company, Racine, Wis., a corporation ofWisconsin Applicatien August 17, 1938, Serial No. 225,473

9 Claims. (Cl. 1 3) This invention relates to stapling machines,particularly for desk use. t

An object of the present invention is to smplify and otherwise improvestapling machines of the type mentioned.

Another object is to provide an eiective, du-

v rable, foolproof stapling machine that may be inexpensively produced.

Other more'specic objects and advantages will appear, expressed orimplied, from the following description of a stapling machineconstructed in accordance with the present invention.

In the accompanying drawing:

Figure 1 is a llongitudinal sectional view of a stapling machineembodying the present invention.

Fig. 2 is a horizontal sectional view taken substantially along the line2 2 of Fig. 1.

Fig. 3 is a Vertical transverse sectional viewv taken substantiallyalong the line 3 3 of Fig. 1.

Fig. 4 is an enlarged sectional View of the lower front portion of thestapling arm shown in Fig. 1, with the plunger in depressed position.

The stap-ling machine selected for illustration comprises a base Il! inthev form of a flanged sheet metal stamping, recessed adjacent oneend toreceive and support I a conventionalv fixed clincher die I I, and havingnot far from its other end a pair of struck-upears I2 between which astapling arm I3 is rockably supported.

In this instance a bolt I4, passing through the ears I2 and through thearm, constitutes a fulcrum support for the latter, and a leaf spring I5,

releasably attached at one end I6 to the base I0 rearwardly of the boltI4, and bearing at its other end I1 ,against the arm I3 forwardly of thebolt, yieldably retains the forward end of the arm elevated above thebase so as to provide the usual entrance throat between the base and arminto which material to be stapled may be entered in the usual manner.'I'he lower end It of the spring is shown engaged in a slot I8 formed inthe base I0 and shaped to provide cantilever support therefor, thespring being retained by -a lug I9 on the base which lug projects intothe slot I8 and through an appropriate hole in the spring I.

The stapling arm` I3 shown is of sheet metal. It compriseslongitudinally extended, laterally spaced, upright side plates 20,joined along their lower margins by an intermediate core member 2|,riveted or otherwise rigidly xed thereto, and additionally rigidlyjoined at their forward ends by a vertical end plate 22 bent to `embraceand substantially close the forward end of the arm and riveted orotherwise fixed thereto. The arm thus constitutes a rigid box-likestructure which is preferably additionally braced by a horizontal 3cross-plate 23 joining upper portions of the side plates 20 not far fromtheir rear ends.

The core member 2| constitutes a support and guide for a conventionaltrain of staples S` and cooperates with the side plates 20 (see Fig. 3)of *.v the arm to form a magazine for the staples. The

core member 2| in this instance comprises a hollow sheet metal stampingof inverted channel form, the upper portion thereof being laterallyreduced to accommodate in the usual manner the Y depending legs of thestaples between it and the -meta1 stamping of inverted `channel formslidably mounted upon and loosely embracing the core member. Thefollower 25 is provided with upstanding ears 26 perforated to slidablyreceive a spring retainer rod 21 having a compression spring 28. thereoninterposed between the rearward ear 26 of the follower and a lugformation 29 on the rod. The rod 21 extends loosely above and lengthwiseof the core 2| and is provided at its forward end with a lug lformation3|) adapted ".to limit the forward advance of the follower 25 byengagement with the forward ear 26 thereof. The rod 21 is positioned bythe earsl 2S on the follower and by an appropriate hook formation 3| atits rear end adapted to releasably engage a perforation 32 in the rearend of the core.

The arrangement is such that the spring 28, acting against the rearfollower ear 25, urges the follower 25 and the staples forwardly, andthus maintains the foremost staple of the train against the forward endplate 22 of the stapling ytical end plate 22 so as toA form therewith anarrow vertical guideway through which the foremost staple of the stapletrain may be vertically ejected. Above this guideway and verticallyaligned therewith is a staple driver 33 which, in the device shown,comprises a steel plate slidalbly seated face-to-face against the endplate 22 and depending from an appropriate actuating plunger 34 to whichit is securely attached by riveting or otherwise. In this instance theplunger 34 is of tubular form, rectangular in cross-section, anddimensioned to provide a close sliding fit within the vertical guidechannel formed by and between the side plates 23 and the end plate 22 ofthe stapling arm. A bolt 35, passing through the side plates and througha Vertical slot 36 in the plunger, retains the plunger in proper workingposition within this guide channel.

The plunger 34 is yieldably retained in the upper position shown by aleaf spring 3'I, releasably held at its lower end 38 in the crossplate23 in a manner similar to the mounting of the spring I5 above described,and reduced at its upper end to form a tongue 39 engaged in anappropriate slot in the plunger 34. The plunger carries an operatinghead 4-preferably eccentrically disposed slightly rearwardly of the axisof the plunger and of the guide bolt 35.

It will of course be understood that papers or other material to bestapled are inserted between the clincher die I I and the elevated endof the stapling arm I3, and that upon applying a downward blow to theplunger head 4I), the end of the stapling arm is vfirst depressed intocontact with the papers, and that thereafter the plunger 34 and driverplate 33 descend through the vertical guideway at the end of the arm 22,driving ahead of it the foremost staple of the train and causing thestaple to penetrate and to be clinched onto the papers in a well knownmanner.

In stapling machines of this type, a return of the plunger and stapledriver to upper position, after a partial depression of the latter, willsometimes permit partial entry of a second staple into the narrowvertical guideway before the foremost staple has been loweredsuiiiciently to clear the second staple. This results in clogging of theguideway. In the machine shown, provision is made to avoid thisdifliculty by automatically returning the first or foremost staple intoits original upper position in the event that it has not been depressedsufficiently to avoid interference with the next staple. For thispurpose, a spring clip 4I is provided (see Figs. 1 and 4), the clipshown being formed of a strip of spring steel bent into loop form withone leg 42 riveted or otherwise attached to the end plate 22 and theother leg 43 extending substantially horizontally through the verticalstaple guideway and through the foremost staple in the staple train. l

The arrangement is such that, as the driver plate 33 is forceddownwardly forcing a staple ahead of it, the staple engages the lowerleg 43 of the clip, depressing the same and deiiecting the clip towardthe position shown in Fig 4, permitting the staple and driver ultimatelyto continue downwardly into staple clinching position. However, in theevent that the driver plate 33 is returned to upper position before thestaple has been depressed clear of the clip, the lower leg 43 of theclip, urging the staple upwardly. causes the staple to follow the driverplate 33 on its upward return movement, and thereby prevents entry of asecond staple into the narrow vertical guideway.

In the machine shown, the stapling arm I3 and parts carried thereby aresubstantially wholly enclosed by an appropriate housing which in thisinstance comprises two separable shells 44 each having an inturnedflange 45 adapted to abut the flange of the other member substantiallythroughout the forward end and top of the housing, the flanges havingappropriate mating recesses to accommodate the clip 4I, the plunger 34,the rear end of the core 2| and associated rod 21 and staple feedmechanism. 'Ihe shells 44 are retained in position preferably by the twobolts I4 and 35 which extend through them.

Various changes may be made in the embodiment of the inventionhereinabove specifically described without departing from or sacrificingthe advantages of the invention as defined in the appended claims.

I claim:

1. In a stapling machine,a stapling arm, a staple magazine extendinglength-wise of and within said arm, staple driving means at one end ofsaid arm operable to eject one staple at a time from said magazine and aresilient clip attached to the same end of said arm, said clipprojecting forwardly from said arm and being doubled back upon itself toform an inwardly directed leg normally projecting across the path oftravel of the ejected staples for the purpose described.

2. In a stapling machine, a stapling arm having a staple magazineextending lengthwise of and within said arm, staple driving means at theforward end of said arm operable to eject staples one at a time fromsaid magazine, and a resilient substantially U-shaped clip having alower leg normally projecting across the path of travel of the ejectedstaples, and a resilient upper leg attached to the forward end of saidarm for resiliently suspending said first named leg forwardly of saidarm.

3. In a stapling machine, a staple arm, a staple magazine extendinglengthwise of and within said arm, staple driving means at the forwardend of said arm operable to eject one staple at a time from saidmagazine, a strip hav- '.ing a portion normally projecting across thepath of travel of the ejected staples and havingr a portion disposedsubstantially forward of said Vpath, and resilient means connecting theforward portion of said strip with said arm and :forming a resilientsuspension for said strip permitting movement of the suspension pointunder the influence of said staple driving means while resilientlyurging said strip into normal position between operations of said stapledriving means.

4. In a stapling machine the combination of a base. a frame rockablysupported on said base and forming a stapling arm, a separate housingattached to and enclosing said frame and rockable therewith, and staplefeeding and driving mechanism carried by said frame independently ofsaid housing, said mechanism being enclosed in said housing andincluding an actuator projecting through said housing.

5. In a stapling machine the combination of a base, a frame forming astapling arm. means including an element for rockably supporting saidarm on said base, a separate housing enclosing said frame and rockabletherewith. means including said element securing said housing to saidframe, and staple feeding and driving mechanism carried by said frameindependently of said housing, said mechanism being enclosed within saidhousing and including actuating means projecting from said housing.

6. In a stapling mechanism, the combination of a base, a clincher diethereon, a stapling arm, means including a bolt for rockably supportingsaid arm on said base, staple driving mechanism including a plungercarried by said arm, a second bolt in said arm for retaining saidplunger in Working position, and a two-part housing carried by androckable with said arm for enclosing said arm and mechanism, each ofsaid bolts extending through both parts of said housing for securingsaid parts together and on said arm.

7. In a device of the character described, the combination with a base,of a stapling head frame tiltable with respect to the base, pintle meansproviding a fulcrum upon which said frame is tiltable, staplingmechanism in the head operatively mounted on the frame, and a casingenclosing said frame and mechanism through which said pintle meansextends, said casing comprising separable parts and said pintle meanscomprising means whereby said parts are secured together.

8. In a device of the character described, the combination with a base,of a tiltable stapling head pivotally connected with the base, a casingcomprising two shallow box-like parts having marginal flanges in edgeabutment and enclosing said head, a rod extending transversely throughthe head, stapling mechanism guided in part on said rod for movementwithin the head, and means at the ends of said rod engaging said casingparts to maintain them in assembly upon the head.

9'. In a device of the character described, the combination with a base,of a stapling head frame pivotally connected with the base for tiltablemovement with respect thereto, stapling mechanism operatively mounted onthe frame to tilt therewith and including a plunger provided With astaple driver and a follower slide provided with a compression springand spring guide rod, and a casing enclosing said frame and stap-lingmechanism and provided with openings for the plunger and the rod, saidcasing comprising shallow box-like parts at opposite sides of the framehaving complementary flanges in marginal abutment, said flanges beingnotched at corresponding points to provide openings for the plunger andthe guide rod respectively, and means for maintaining said casing partsin assembly.

ROY G. HOFFERT.

